I had some queries regarding public DNS records I was hoping someone could help me with.
Let's say my domain is kam.com and my ISP is Verizon. Their public DNS servers are DNS1 and DNS2.
Would I be correct in thinking that the authorative DNS servers for the kam.com domain/zone are DNS1 and DNS2?
But I'm not sure how SOA records fit into this?
Let's say Kam.com was a masssive company and I had my own public DNS servers on the internet (is this common?) - DNS3 and DNS4.
Again, the authorative servers for kam.com would be DNS3 and DNS4.
Authorative servers means that when someone queries DNS info for kam.com (e.g. a machine wants to resolve www.kam.com
), they are directed to the authorative servers for that domain? What would happen if these servers would be unavailable? Is the information not cached somewhere? In which case, why don't public computers query the cached info first?